Grab



n. BARNARDQ GRAB.

APPLICATION FILED JULY 14,1920.

Pmnted Sept. 21, 392%.,

3 SBEETS -SHEET 1.

AVVLWTUR D. J. BARNARD.

GRAB.

APPLICATION FILED IULY I4, 1920.

'3 SHEETS-SHEET 2- ?amnted Sept 21, 192% D J. BARNARD.

GRAB.

APPLICATION ElLEu lllLY 14. 1920.

Pamntefl $6M. 21, 19%.

' a swam-sum 3.

' ency on the part of the beam and power guide said parts into correct position for. en;

marina stares DUDLEY- JAMES BARN'ARD,

or BARKiNGr, ENGL ND.

WGRAIB. Y

dens, Barking, in the county of Essex, Eng

land, engineer, have invented certain new and useful Improvements in and Relating to Grabs, ofwhich the following is a specification. a

This invention relates to grabs of what is known as the single chain'type, that is to say, a grab in which all movements are effected by means of a single chain or rope.

The objects of this invention are to simplify the general construction of the opera tive parts of the grab, to obviate any tendshaft to over-balance, and to more effectively gagement with the locking mechanism. I

' The invention further consists in the provision of an improved form oftipping mech anism by means of which the powershaft may be automatically disconnected from. the bucket sections for the purpose of opening. the buckets.

Broadly the invention consists of a pair of telescopic members arranged on each side of the grab, one part of each pair being car: ried by links mounted between the top cross" members or bars and the other part bythe cross beam. The rigidity of the spreader. arms of the grab is further assured by the provision of a pair of links pivoted to the arms approximately at thetop thereof.

The trip mechanism accordingto 'thisinvention consists of a lever, hereafter referred to as the trip lever, furnishedatits upper extremity with a hook-shapedpart adapted to co-act with-a tipping ringsuspended by means of chains from-a centralizing member carried by or hung from the jib of the crane. The hook-shaped member islarranged to pass through the ring and'when raised to the required extent, the ring is drawn under the hook b I, the action of the centralizing member. I a vertically disposed link,.pivoted to the other end of the trip-lever, coacts with an extension on'the gravity catch. In the accompanying drawingwhich illustrates one embodiment ofthe invention I Figure 1 is a sideelevationshowing the bucket sections of the grab in closed posi tion. 1 Fig. 2 is a front elevation of Fig. 1, cer- Specificati on of Letters Patent.

'and held together by the bolts 20.

atented Sept 21, 1920.

Application filed ui 14, 1920. Serial No. 396,296.

Mimi erase tain parts being omitted to enable the esse1i-' I tial features to be more clearly illustrated.

Fig. 3 is a similar viewshowing the bucket sections in open position, but with the power, shaft inthe normal position, with certain parts omitted.

In the'drawings Land 2 the bucket sections pivoted on independent pins 3, 4 on. a cross beam 5; 6 and 7 are the top-cross bars and 8 the spreader arms, one at each outer corner of the bucket sections.

Supported by the top-cross bars 6 and 7 in any desired manner, such as by the plates 9, 1O spaced and held together by the bolts 11, is a set of. purchase sheaves 12, mounted on the spindle 13. .The co-acting or. power shaves. 14, 15., are mounted on the spindles spaced 16, 17 carried'by the plates 18, 19,

. The power shafts or studs-21, on which thegravity catches are mounted, are also parts connected to the plates carried on.

i The means for maintaining the normal balance of the operative parts comprises two vertically disposed telescopic devices ar-' 7 ranged one on each'side of'the grab, one

member 23 of each device beingcarried by horizontally disposed plates or links'24, 25, mounted on the top-cross members 6 and 7, the' other member 26 of each ,device being carried by the parts 27 mounted on the cross beam 5, thefsaid .members 23, 26 passing through sleeves'or thimbles 28,29, carried by the plates 18 and 19 respectively.

Two of the spreader arms 8, one on each side of the grab, are furnished with extending portions 30, 31, to each of'which, one end of a pair of links 32, .33 is pivoted, the other, ends of such links being Q'pivoted' at 34: and 35 respectively,:to thespreader arms pivots forthe arms on I at a point: below the the top-cross bars. I ,The" gravity catches which-constitute the means for maintaining, the bucket sections 1 and 2 intlosed position are each provided with 3 operative parts, a catch or supporting hook 22, an extending lever-.22 .andfa projection 22 g The hooks 22am adapted to engagewith the pins 36 .c'arried by the parts 27 and the extending levers 22* are adapted toco-act with the lower end of .a lever 43. The projections 22 are .adapted to o e; with members 51 carried by vertically disposed members 52 sliding in guides 53,

hooked end 38 of the trip lever is mounted on the parts 28 and 29, said members 52 being controlled by springs 5%, the top end of each spring being connected to the guides 53 and the lower end to the member 52. Then the grab is closed or, until the power sheaves have been lowered for the purpose of closing the grab, the members 52 are depressed against the action of the springs 54 by stops 55 mounted on the plates 9 and 10. lVhen the power sheaves are lowered, the, action of the springs causes the members 51 to be brought up against the projections 22 and thereby cause the hooks 22 to be drawn under the pins 36.

The trip mechanism according to this invention consists of a lever 37, furnished at its upper extremity with a hook shaped part 38 adapted to co-act with the inner edge 39 of tipping ring 4:0 suspended by means of chains 4:1 from a centralizing member 42 carried by or hung from the jib of the crane.

The trip lever 37 is pivotally connected to the plate'9, and a further lever i3 is pivotally connected to its other end, which lever is adapted to co-act with the gravity catches 22, so that when the trip lever is actuated by the tipping ring the gravity catches are depressed and released from the pins 36 and the bucket sections, having lost their meansof support, fall into the open position. The lever L3 is maintained in operative position with relation to the gravity catches by means of a pin 4 providedon the framework of the grab, said pin sliding in a slot 4E5 provided in the lever 45.

The centralizing member 42 above re ferred to is preferably of plate form and is provided with a centrally disposed thimble 46 through which the rope 47 isadapted to pass. V

T o centralize therope 4:7 with respect to the grab, a pair of horizontally'disposed links or plates 4L8, 49, are mounted on the top-cross bars 6-, 7, to which plates a two part thimble 50 is bolted in any desired manner.

The thimble 50 is formed in two parts so that the eye on the extreme end of the rope may be passed through. r 7 I When the parts are in position shown in Fig. 1, and the entire grab is raised, the

brought 40 which is thereby displaced laterally until it falls over the hook, as shown by dotted lines in Fig. ,1, under which it is drawn by the action of the centralizing member 4:2. I v

If the grab is now lowered, the resistance offered by the ring 40 causes the trip lever 37 to turn on its pivot and the lower end-is forced downward against thelever forming an extension or part of the gravity catch which it depresses in the manner above referred to.

As the against the ring,

bucket sections fall, the tubular members 26 slide downwardly over the members 23 and in the sleeves 28 29, until they occupy the position shown in Fig. 3.

By the arrangement above described it will be obvious that the parts must be maintained in balanced position irrespective of the angle which the grab may take up while resting on a heap, the parts being by this means held in the correct position for engagement with the locking mechanism when it is desired to close the grab.

I claim 1. In a grab of the kind herein described, the combination of means connecting the cross-beam the power shaft and the top crossbars comprising two vertically disposed telescopic devices arranged one on each side of the grab one member of each device being carried by links mounted between the top cross bars and the other members being carried by the cross beam and means for guiding said beam and said power shaft comprising sleeves or thimbles carried by the frame in which the power sheaves are mounted and adapted to form guides for the telescopic members.

2. In a grab of the kind herein described, the combination of means. connecting the crossbeam the power shaft and the top cross bars comprising two vertically disposed telescopic devices arranged one on each side of the grab one member of each device being carried by the links mounted between the top cross bars and the other members being carried by the cross beam, means for guiding said beam and said power shaft comprising sleeves or thimbles carried by the frame in which the power sheaves are mounted and adapted to form guides for the telescopic members, means for locking. said beam and power shaft together, and means for disconnecting such locking means.

3. In a grab of the kind herein described, the combination of means connecting the cross-beam the power shaft and the top cross bars comprising two vertically disposed telescopic devices arranged one on each side of the grab one member of each device being carried by links mounted between the top Crossbars and the other member being carried by the cross beam, means for guiding said beam, and said power shaft comprising sleeves or thimbles carried by the frame in which the power sheaves are mounted and adapted to form guides for the telescopic members, and means for centralizing the suspending rope with respect to the tipping ring comprising a plate having a centrally disposedtwo-part thimble through which the rope passes.

4i. Ina grab of the kind herein described, the combination of means connecting the cross-beam the power shaft and the top cross bars comprising two vertically disposed telescopic devices arranged one on each side of the grab one member of each device being carried by links mounted between the top cross bars and the other member being carand power shaft together, and means for I disconnecting such locking means.

5. In a grab of the kind herein described,

the combination of means connecting the I cross-beam the powershaft and the top cross bars comprising two vertically disposed telescopic devices arranged one on each side of the grab one member of each device being carried by links mounted between the top cross bars and the other member being carried by the cross beam, means for guiding saidbeam and said power shaft comprising sleeves or thimbles carried by the frame in which the power sheaves are mounted and adapted to form guides for the telescopic members, means for locking said beam and power shaft together, means for centralizingthe suspending rope with respect to the tipping ring comprising a plate having a centrally disposed two part thimble through which the rope passes, and tipping mechanism comprising a ring suspended from the centralizing member and a lever having a:

c hook-shaped part at its upper end adapted to coact with the inner edge of said tipping ring.

6. In a grab of the kind herein described, the combination of means connecting the cross-beam the power shaft and the top cross bars comprising two vertically disposed telescopic devices arranged one on, each side of the grab one member of each device being.

carried by links mounted between the top cross bars and the other member being carried by the cross beam, means for guiding said beam and said power shaft comprising sleeves or thimbles carried by the frame in of the which the power sheaves are mounted and adapted to form guides for the; telescopic members, means for locking said beam and shaft together, means for centralizing the suspending rope with respect to'the tipping rmg comprismg a plate having a centrally disposed two-part thimble through which the rope passes, tipping mechanism compris-,

mg a ring suspended from the centralizing member and a lever having a hook-shaped part at its upper end adapted to co-act with the inner edge of said tipping ring, and means for imparting rigidity to the spreader comprising a pair of links each pivoted to r i the pair of spreader arms on one side of the grab the points of pivot of each link being respectively above and below the points of I pivot of the pairs of arms to which they are connected. I I

7. In a grab of the kind'herein described,

the combination of means connecting the cross-beam the power shaft'a-nd the top cross bars comprising two vertically disposed telescopic devices arranged one on each side of the grab one memberof each devicebeing carried bylinks mounted between the top 1 cross. bars and the other member being carried by the cross beam, means for guiding said beam and said powersha-ft comprising sleeves or thimbles carried by the frame in which the power sheaves are mounted and adapted to form guides for the telescopic members. means comprising gravity catches for locking said beam and said power shaft together, means comprising a tipping ring with whicha trip lever coacts for disconnecting such locking means, means for centralizing the suspending rope with respect to the tipping ring comprising a plate having a centrally disposed two-part thimble through which the rope passes, and means i for impartlng rigidity to the spreader com prising a pair of links each pivoted to the pair of spreader arms on one side of the grab the points of each link being respec tively above and below the points of pivot pairs of arms to which they are connected. 1

DUDLEY JAMES BARNARD. 

